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Kim JH, Previte DJ, Yoon KS, Murenzi E, Koehler JE, Pittendrigh BR, Lee SH, Clark JM. Comparison of the proliferation and excretion of Bartonella quintana between body and head lice following oral challenge. INSECT MOLECULAR BIOLOGY 2017; 26:266-276. [PMID: 28105732 PMCID: PMC5400725 DOI: 10.1111/imb.12292] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Human body and head lice are highly related haematophagous ectoparasites but only the body louse has been shown to transmit Bartonella quintana, the causative agent of trench fever. The mechanisms by which body lice became a vector for B. quintana, however, are poorly understood. Following oral challenge, green fluorescent protein-expressing B. quintana proliferated over 9 days postchallenge with the number of bacteria being significantly higher in whole body vs. head lice. The numbers of B. quintana detected in faeces from infected lice, however, were approximately the same in both lice. Nevertheless, the viability of B. quintana was significantly higher in body louse faeces. Comparison of immune responses in alimentary tract tissues revealed that basal transcription levels of peptidoglycan recognition protein and defensins were lower in body lice and the transcription of defensin 1 was up-regulated by oral challenge with wild-type B. quintana in head but not in body lice. In addition, the level of cytotoxic reactive oxygen species generated by epithelial cells was significantly lower in body lice. Although speculative at this time, the reduced immune response is consistent with the higher vector competence seen in body vs. head lice in terms of B. quintana infection.
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Affiliation(s)
- J H Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
| | - D J Previte
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, MA, USA
| | - K S Yoon
- Department of Biological Sciences and Environmental Sciences Program, Southern Illinois University-Edwardsville, Edwardsville, IL, USA
| | - E Murenzi
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, MA, USA
| | - J E Koehler
- Microbial Pathogenesis and Host Defense Program, and Division of Infectious Diseases, Department of Medicine, University of California, San Francisco, CA, USA
| | - B R Pittendrigh
- Department of Entomology, University of Illinois Urbana-Champaign, Urbana, IL, USA
| | - S H Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
- Research Institute for Agriculture and Life Science, Seoul National University, Seoul, Korea
| | - J M Clark
- Department of Veterinary & Animal Science, University of Massachusetts, Amherst, MA, USA
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A SacB mutagenesis strategy reveals that the Bartonella quintana variably expressed outer membrane proteins are required for bloodstream infection of the host. Infect Immun 2007; 76:788-95. [PMID: 18070893 DOI: 10.1128/iai.01174-07] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Bartonella bacteria adhere to erythrocytes and persistently infect the mammalian bloodstream. We previously identified four highly conserved Bartonella quintana adhesin genes that undergo phase variation during prolonged bloodstream infection. The variably expressed outer membrane proteins (Vomp) encoded by these genes are members of the trimeric autotransporter adhesin family. Each B. quintana Vomp appears to contribute a different adhesion phenotype, likely mediated by the major variable region at the adhesive tip of each Vomp. Although studies document that the Vomp adhesins confer virulence phenotypes in vitro, little is known about in vivo virulence strategies of Bartonella. We sought to determine whether the B. quintana Vomp adhesins are necessary for infection in vivo by using a vomp null mutant. It first was necessary to develop a system to generate in-frame deletions of defined genes by allelic exchange in a wild-type Bartonella background, which had not been achieved previously. We utilized sacB negative selection to generate a targeted, in-frame, markerless deletion of the entire vomp locus in B. quintana. We also recently developed the first animal model for B. quintana infection, and using this model, we demonstrate here that the deletion of the entire vomp locus, but not the deletion of two vomp genes, results in a null mutant strain that is incapable of establishing bloodstream infection in vivo. The Vomp adhesins therefore represent critical virulence factors in vivo, warranting further study. Finally, our allelic exchange strategy provides an important advance in the genetic manipulation of all Bartonella species and, combined with the animal model that recapitulates human disease, will facilitate pathogenesis studies of B. quintana.
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Battisti JM, Smitherman LS, Sappington KN, Parrow NL, Raghavan R, Minnick MF. Transcriptional regulation of the heme binding protein gene family of Bartonella quintana is accomplished by a novel promoter element and iron response regulator. Infect Immun 2007; 75:4373-85. [PMID: 17576755 PMCID: PMC1951173 DOI: 10.1128/iai.00497-07] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
We previously identified a five-member family of hemin-binding proteins (Hbp's) of Bartonella quintana that bind hemin on the outer surface but share no homology with known bacterial heme receptors. Subsequently, we demonstrated that expression of the hbp family is significantly influenced by oxygen, heme, and temperature conditions encountered by the pathogen in the human host and the body louse vector; e.g., we observed a dramatic (>100-fold) increase in hbpC transcript levels in response to the "louse-like" temperature of 30 degrees C. The goal of the present study was to identify a transcription factor(s) involved in the coordinated and differential regulation of the hbp family. First, we used quantitative real-time PCR (qRT-PCR) to show that the same environmental conditions generate parallels in the transcript profiles of four candidate transcriptional regulators (Irr, Fur, RirA, and BatR) described in the order Rhizobiales, with the greatest overall change in the transcription of irr (a >5-fold decrease) at a "louse-like" temperature, suggesting that Irr may function as an hbpC repressor. Second, a B. quintana strain hyperexpressing Irr was constructed; it exhibits a "bloodstream-like" hbp transcript profile in the absence of an environmental stimulus (i.e., hbpC is repressed and hbpA, hbpD, and hbpE mRNAs are relatively abundant). Furthermore, when this strain is grown at a "louse-like" temperature, an inversion of the transcript profile occurs, where derepression of hbpC and repression of hbpA, hbpD, and hbpE are readily evident, strongly suggesting that Irr and temperature influence hbp family expression. Third, electrophoretic mobility shift analyses show that recombinant Irr binds specifically to the hbpC promoter region at a sequence that is highly conserved in Bartonella hbp genes, which we designated the hbp family box, or "H-box." Fourth, we used the H-box to search the B. quintana genome and discovered a number of intriguing open reading frames, e.g., five members of a six-member family of cohemolysin autotransporters. Finally, qRT-PCR data regarding the effects of Fur and RirA overexpression on the hbp family are provided; they show that Fur's effect on the hbp family is relatively minor but RirA generates a "bloodstream-like" hbp transcript profile in the absence of an environmental stimulus, as observed for the Irr-hyperexpressing strain.
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Affiliation(s)
- James M Battisti
- Division of Biological Sciences, The University of Montana, Missoula, MT 59812, USA
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Eremeeva ME, Gerns HL, Lydy SL, Goo JS, Ryan ET, Mathew SS, Ferraro MJ, Holden JM, Nicholson WL, Dasch GA, Koehler JE. Bacteremia, fever, and splenomegaly caused by a newly recognized bartonella species. N Engl J Med 2007; 356:2381-7. [PMID: 17554119 DOI: 10.1056/nejmoa065987] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Bartonella species cause serious human infections globally, including bacillary angiomatosis, Oroya fever, trench fever, and endocarditis. We describe a patient who had fever and splenomegaly after traveling to Peru and also had bacteremia from an organism that resembled Bartonella bacilliformis, the causative agent of Oroya fever, which is endemic to Peru. However, genetic analyses revealed that this fastidious bacterium represented a previously uncultured and unnamed bartonella species, closely related to B. clarridgeiae and more distantly related to B. bacilliformis. We characterized this isolate, including its ability to cause fever and sustained bacteremia in a rhesus macaque. The route of infection and burden of human disease associated with this newly described pathogen are currently unknown.
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Ledala N, Pearson SL, Wilkinson BJ, Jayaswal RK. Molecular characterization of the Fur protein of Listeria monocytogenes. Microbiology (Reading) 2007; 153:1103-1111. [PMID: 17379719 DOI: 10.1099/mic.0.2006/000620-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Iron is essential for the survival of almost all organisms, although excess iron can result in the generation of free radicals which are toxic to cells. To avoid the toxic effects of free radicals, the concentration of intracellular iron is generally regulated by the ferric uptake regulator Fur in bacteria. The 150 aa fur ORF from Listeria monocytogenes was cloned into pRSETa, and the His-tagged fusion protein was purified by nickel affinity column chromatography. DNA binding activity of this protein was studied by an electrophoretic mobility shift assay using the end-labelled promoters P(fhuDC) and P(fur). The results showed a decrease in migration for both promoter DNAs in the presence of the Fur protein, and the change in migration was competitively inhibited with an excess of the same unlabelled promoters. No shift in migration was observed when a similar assay was performed using non-specific end-labelled DNA. The assay showed that binding of Fur to P(fur) or P(fhuDC) was independent of iron or manganese ions, and was not inhibited in the presence of 2 mM EDTA. Inductively coupled plasma MS of the Fur protein showed no iron or manganese, but 0.48 mole zinc per mole protein was detected. A DNase I protection assay revealed that Fur specifically bound to and protected a 19 bp consensus Fur box sequence located in the promoters of fur and fhuDC. There was no requirement for iron or manganese in this assay also. However, Northern blot analysis showed an increase in fur transcription under iron-restricted compared to high-level conditions. Thus, the study suggests that under in vitro conditions, the affinity of the Fur protein for the 19 bp Fur box sequence does not require iron, but iron availability regulates fur transcription in vivo. Thus, the regulation by Fur in this intracellular pathogen may be dependent on either the structure of the DNA binding domain or other intracellular factors yet to be identified.
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Affiliation(s)
- Nagender Ledala
- Microbiology Group, Department of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
| | - Stacy L Pearson
- Microbiology Group, Department of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
| | - Brian J Wilkinson
- Microbiology Group, Department of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
| | - R K Jayaswal
- Microbiology Group, Department of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
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Díaz-Mireles E, Wexler M, Todd JD, Bellini D, Johnston AWB, Sawers RG. The manganese-responsive repressor Mur of Rhizobium leguminosarum is a member of the Fur-superfamily that recognizes an unusual operator sequence. MICROBIOLOGY-SGM 2006; 151:4071-4078. [PMID: 16339952 DOI: 10.1099/mic.0.28342-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The manganese uptake regulator Mur of Rhizobium leguminosarum is a close homologue of the global iron regulatory protein Fur. Mur represses the sitABCD operon, which encodes a Mn2+ transport system, specifically in response to Mn2+ but not Fe2+. In previous work the authors mapped the 5' ends of two sit operon transcripts, termed TS1 and TS2, which were co-ordinately regulated by Mn2+-Mur, but this paper now shows that only TS1 is a primary transcript. DNase I protection analyses showed that purified Mur bound, with similar affinity, to two sites in the regulatory region of sitABCD, but only when Mn2+ was present in the reaction buffer. These Mn2+-Mur-binding sites, termed MRS1 and MRS2 (Mur-responsive sequence), were closely related in sequence to each other and were separated by 16 bp, spanning the transcription initiation site TS1. The extent of the protected DNA was 34 and 31 bp for MRS1 and MRS2, respectively, which is in accord with other members of the Fur family. The DNA sequences recognized by Mn2+-Mur are wholly different from conventional Fur boxes, but some similarities to a recognition sequence for the Fur regulator from Bradyrhizobium japonicum were noted. Transcription analysis of the R. leguminosarum mur gene showed its expression to be independent of Mn2+-Mur. Thus, Mur is a sequence-specific DNA-binding protein that responds in vitro to manganese, and thus can occlude RNA polymerase access to the sitABCD promoter. Moreover, Mur recognizes a DNA sequence atypical for the Fur superfamily and, like Fur from B. japonicum, defines a new subclass of Fur-like transcriptional regulators.
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Affiliation(s)
- Edit Díaz-Mireles
- School of Biological Science, University of East Anglia, Norwich NR4 7TJ, UK
| | - Margaret Wexler
- School of Biological Science, University of East Anglia, Norwich NR4 7TJ, UK
| | - Jonathan D Todd
- School of Biological Science, University of East Anglia, Norwich NR4 7TJ, UK
| | - Dominico Bellini
- School of Biological Science, University of East Anglia, Norwich NR4 7TJ, UK
| | - Andrew W B Johnston
- School of Biological Science, University of East Anglia, Norwich NR4 7TJ, UK
| | - R Gary Sawers
- Department of Molecular Microbiology, John Innes Centre, Colney Lane, Norwich NR4 7UH, UK
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Platero R, Peixoto L, O'Brian MR, Fabiano E. Fur is involved in manganese-dependent regulation of mntA (sitA) expression in Sinorhizobium meliloti. Appl Environ Microbiol 2004; 70:4349-55. [PMID: 15240318 PMCID: PMC444773 DOI: 10.1128/aem.70.7.4349-4355.2004] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Fur is a transcriptional regulator involved in iron-dependent control of gene expression in many bacteria. In this work we analyzed the phenotype of a fur mutant in Sinorhizobium meliloti, an alpha-proteobacterium that fixes N(2) in association with host plants. We demonstrated that some functions involved in high-affinity iron transport, siderophore production, and iron-regulated outer membrane protein expression respond to iron in a Fur-independent manner. However, manganese-dependent expression of the MntABCD manganese transport system was lost in a fur strain as discerned by constitutive expression of a mntA::gfp fusion reporter gene in the mutant. Thus, Fur directly or indirectly regulates a manganese-dependent function. The data indicate a novel function for a bacterial Fur protein in mediating manganese-dependent regulation of gene expression.
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Affiliation(s)
- Raúl Platero
- Laboratorio de Ecología Microbiana, Instituto de Investigaciones Biológicas Clemente Estable, MEC, Unidad Asociada a la Facultad de Ciencias, Montevideo 11600, Uruguay
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Zhang P, Chomel BB, Schau MK, Goo JS, Droz S, Kelminson KL, George SS, Lerche NW, Koehler JE. A family of variably expressed outer-membrane proteins (Vomp) mediates adhesion and autoaggregation in Bartonella quintana. Proc Natl Acad Sci U S A 2004; 101:13630-5. [PMID: 15347808 PMCID: PMC518805 DOI: 10.1073/pnas.0405284101] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2004] [Indexed: 11/18/2022] Open
Abstract
Bartonella species are fastidious, Gram-negative human pathogens that can persist in the host bloodstream for years and bind to and invade several types of host cells. For many pathogens, adhesion to host cells and extracellular matrix (ECM) components is a critical virulence determinant. Bacteria often vary expression of surface adhesins by phase or antigenic variation to subvert the host immune response and permit adaptive interaction with different host structures. We developed a macaque animal model for Bartonella quintana infection to detect changes in bacterial outer-membrane proteins (OMP) during prolonged bloodstream infection. We identified a gene family encoding four highly conserved, 100-kDa, variably expressed OMP (Vomp), two of which function as adhesins. The variable expression of Vomp family members appears to be mediated by deletion of one or more vomp genes during chronic bloodstream infection. vomp deletion was observed also in isolates from humans with chronic B. quintana infection. The Vomp are closely related to the afimbrial adhesin, YadA, a virulence factor of Yersinia enterocolitica. The surface-expressed Vomp contain conserved structural features of YadA, including collagen-binding motifs. We demonstrate that the B. quintana Vomp are multifunctional OMP involved in binding to collagen and autoaggregation: VompC confers the ability to bind collagen IV, and VompA is necessary and sufficient for autoaggregation. The B. quintana Vomp are members of the newly recognized family of YadA-like trimeric autotransporters; the Vomp constitute a multigene family, they are variably expressed, and different virulence properties are attributable to individual Vomp family members.
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Affiliation(s)
- Peng Zhang
- Division of Infectious Diseases, Department of Medicine, University of California-San Francisco, 521 Parnassus Avenue, San Francisco, CA 94143-0654
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Chao TC, Becker A, Buhrmester J, Pühler A, Weidner S. The Sinorhizobium meliloti fur gene regulates, with dependence on Mn(II), transcription of the sitABCD operon, encoding a metal-type transporter. J Bacteriol 2004; 186:3609-20. [PMID: 15150249 PMCID: PMC415740 DOI: 10.1128/jb.186.11.3609-3620.2004] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sinorhizobium meliloti is an alpha-proteobacterium able to induce nitrogen-fixing nodules on roots of specific legumes. In order to propagate in the soil and for successful symbiotic interaction the bacterium needs to sequester metals like iron and manganese from its environment. The metal uptake has to be in turn tightly regulated to avoid toxic effects. In this report we describe the characterization of a chromosomal region of S. meliloti encoding the sitABCD operon and the putative regulatory fur gene. It is generally assumed that the sitABCD operon encodes a metal-type transporter and that the fur gene is involved in iron ion uptake regulation. A constructed S. meliloti sitA deletion mutant was found to be growth dependent on Mn(II) and to a lesser degree on Fe(II). The sitA promoter was strongly repressed by Mn(II), with dependence on Fur, and moderately by Fe(II). Applying a genome-wide S. meliloti microarray it was shown that in the fur deletion mutant 23 genes were up-regulated and 10 genes were down-regulated when compared to the wild-type strain. Among the up-regulated genes only the sitABCD operon could be associated with metal uptake. On the other hand, the complete rhbABCDEF operon, which is involved in siderophore synthesis, was identified among the down-regulated genes. Thus, in S. meliloti Fur is not a global repressor of iron uptake. Under symbiotic conditions the sitA promoter was strongly expressed and the S. meliloti sitA mutant exhibited an attenuated nitrogen fixation activity resulting in a decreased fresh weight of the host plant Medicago sativa.
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Affiliation(s)
- Tzu-Chiao Chao
- Lehrstuhl für Genetik, Fakultät für Biologie, Universität Bielefeld, D-33501 Bielefeld, Germany
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Zimmermann R, Kempf VAJ, Schiltz E, Oberle K, Sander A. Hemin binding, functional expression, and complementation analysis of Pap 31 from Bartonella henselae. J Bacteriol 2003; 185:1739-44. [PMID: 12591895 PMCID: PMC148071 DOI: 10.1128/jb.185.5.1739-1744.2003] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Growth of Bartonella henselae is strongly heme dependent, and B. henselae is unable to synthesize heme itself. At least five outer membrane-associated proteins from B. henselae bind hemin, including the 31-kDa protein designated Pap31. The gene of this protein was heterologously expressed in Escherichia coli M15(pREP4) and detected with monoclonal antibodies in the outer membrane fraction. Complementation of the hemA-deficient mutant E. coli K-12 EB53 (aroB tsx malT hemA) with pap31 demonstrated that this protein is involved in heme acquisition and may be an important virulence factor in the pathogenesis of B. henselae.
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Affiliation(s)
- Rainer Zimmermann
- Institute of Medical Microbiology and Hygiene, University of Freiburg, Freiburg, Germany
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